perf(scenes): bounded count + has_more for filtered scene lists

Filtered /scenes (tag/origin/q/studio/performer) ran exhaustive COUNT with
stub-filter EXISTS over 1.7M rows: TAG 5.1s, ORIGIN 4.9s, SEARCH 3.1s.
Mobile relied on `loaded < total` for infinite-scroll, making exact count
mandatory and ruling out approximate shortcuts.

Backend:
- SceneListOut gains has_more (bool) and total_capped (bool), both optional
  for backward compat with old mobile
- Filtered count uses LIMIT _COUNT_CAP+1 (1000) subquery — cost is
  O(min(matches, cap)) instead of O(all). Measured: TAG 5.1s→664ms,
  SEARCH 3.1s→138ms, ORIGIN 4.9s→1.07s (also fixes SiteScenes showing
  global count ~1M instead of per-site count)
- has_more from fetching per_page+1 rows (essentially free); extra row
  stripped before serialisation
- Pure-default list (no filters at all) keeps TTL-cached full count

Mobile:
- getNextPageParam uses has_more ?? fallback to loaded<total
- Display shows "{total}+" when total_capped=true (5 screens)

Verified on emulator: tag "Big Tits" → "1000 scenes" loaded, no 500s,
backward compat confirmed (old APK works against new backend).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/api/scenes.py

@@ -46,6 +46,13 @@ _VALID_SORTS = {"created_at", "release_date", "title", "studio"}
 _DEFAULT_COUNT_CACHE: dict = {"ts": 0.0, "val": 0}
 _DEFAULT_COUNT_TTL = 600.0
 
+# Bounded count dla list FILTROWANYCH (origin/tag/q/studio/performer/...). Exhaustive
+# count z per-row stub-filter EXISTS bierze ~3-5s przy 1.7M scen (zmierzone). Liczymy
+# count tylko do CAP+1 — `LIMIT` ucina po znalezieniu CAP+1 pasujących, więc koszt to
+# O(min(matches, CAP)) zamiast O(all). >CAP → UI pokazuje "{CAP}+". Paginacja idzie po
+# has_more (fetch per_page+1), więc bounded total NIE psuje infinite-scroll.
+_COUNT_CAP = 1000
+
 
 def _default_scene_count(session: Session) -> int:
     import time as _time
@@ -303,20 +310,31 @@ def list_scenes(
             Scene.release_date.is_not(None) | canonical_exists | has_performer
         )
 
-    # Count: dla dużych baz (~400k scen) pełny count z 3 nested EXISTS bierze ~5s.
+    # Count strategy:
-    # Liczymy total na uproszczonym query (bez stub-filter w count) — daje ~5% off
+    #  - PURE default (brak jakiegokolwiek filtra): cached count całego katalogu
-    # ale jest akceptowalne dla user-facing pagination header. Items query NADAL
+    #    (full-scan + EXISTS ~950ms, TTL 10 min — patrz _default_scene_count).
-    # ma stub-filter, więc lista pokazuje poprawne sceny. Liczba w header jest
+    #  - FILTROWANE (origin/tag/q/studio/performer/quality/duration/...): bounded
-    # przybliżoną górną granicą — co dla 400k scen i tak nie ma sensu reading dokładnie.
+    #    count do _COUNT_CAP. Exhaustive count z per-row stub EXISTS to ~3-5s; bounded
-    if not include_stubs and not q and not studio_slug_list and not tags and not perf_id_strings:
+    #    ucina po CAP+1 trafieniach. Mobile paginuje po has_more (niżej), nie po total,
-        # Fast path: typowy default request (lista bez filtra) — count tylko po
+    #    więc cap nie psuje infinite-scroll.
-        # has_playback (single EXISTS). Mimo to przy 1.69M scen full-scan z EXISTS
+    _is_pure_default = (
-        # bierze ~950ms (zmierzone 2026-05-31), a liczba zmienia się wolno (ingest
+        not include_stubs and not q and not studio_slug_list and not tag_slug_list
-        # ~kilkadziesiąt scen/h) i jest z definicji przybliżona. TTL-cache 10 min:
+        and not perf_id_strings and origin is None and has_playback is None
-        # pierwszy request po wygaśnięciu płaci ~950ms, reszta czyta z pamięci.
+        and not has_animated_thumbnail and min_duration_sec is None
+        and max_duration_sec is None and released_within_days is None
+        and min_quality_p is None
+    )
+    total_capped = False
+    if _is_pure_default:
         total = _default_scene_count(session)
     else:
-        total = session.execute(select(func.count()).select_from(base.subquery())).scalar_one()
+        cnt = session.execute(
+            select(func.count()).select_from(base.limit(_COUNT_CAP + 1).subquery())
+        ).scalar_one()
+        if cnt > _COUNT_CAP:
+            total, total_capped = _COUNT_CAP, True
+        else:
+            total = cnt
 
     # Sort: zawsze tie-break po created_at desc dla determinizmu paginacji.
     if sort == "release_date":
@@ -340,15 +358,27 @@ def list_scenes(
             Scene.created_at.desc(), Scene.release_date.desc().nullslast()
         )
 
+    # Fetch per_page+1 — obecność (per_page+1)-szego wiersza = jest kolejna strona.
+    # To źródło prawdy dla paginacji (mobile getNextPageParam), niezależne od bounded
+    # `total`. Nadmiarowy wiersz odcinamy przed serializacją.
     rows = (
-        session.execute(ordered.offset((page - 1) * per_page).limit(per_page))
+        session.execute(ordered.offset((page - 1) * per_page).limit(per_page + 1))
         .scalars()
         .all()
     )
+    has_more = len(rows) > per_page
+    rows = rows[:per_page]
 
     items = _build_scenes_out_batch(session, list(rows))
 
-    return SceneListOut(items=items, total=total, page=page, per_page=per_page)
+    return SceneListOut(
+        items=items,
+        total=total,
+        page=page,
+        per_page=per_page,
+        has_more=has_more,
+        total_capped=total_capped,
+    )
 
 
 @router.get("/{scene_id}", response_model=SceneOut)

app/api/schemas.py

@@ -83,6 +83,12 @@ class SceneListOut(BaseModel):
     total: int
     page: int
     per_page: int
+    # has_more: czy istnieje kolejna strona. Liczone z fetcha per_page+1 (≈darmowe),
+    # NIE z `total` — bo dla filtrowanych list `total` jest bounded ("1000+") żeby
+    # uniknąć ~5s exhaustive count. Mobile paginuje po has_more, nie po total.
+    has_more: bool = False
+    # total_capped: True gdy `total` to bounded cap (są >total wyników). UI: "{total}+".
+    total_capped: bool = False
 
 
 class MovieChapterOut(BaseModel):

mobile/src/screens/PerformerScenesScreen.tsx

@@ -223,6 +223,7 @@ export function PerformerScenesScreen() {
 
   const movies = moviesQuery.data?.items ?? [];
   const scenesTotal = scenesQuery.data?.total ?? 0;
+  const scenesSuffix = scenesQuery.data?.total_capped ? '+' : '';
   const moviesTotal = moviesQuery.data?.total ?? 0;
 
   // Bug-report 2026-05-17 (562cf95c): "Przy przełączaniu na movies app crashed".
@@ -283,7 +284,7 @@ export function PerformerScenesScreen() {
                 <View style={styles.header}>
                   <Text style={styles.subtitle}>
                     {scenesQuery.data
-                      ? `${scenesTotal} ${scenesTotal === 1 ? 'scene' : 'scenes'}`
+                      ? `${scenesTotal}${scenesSuffix} ${scenesTotal === 1 ? 'scene' : 'scenes'}`
                       : ' '}
                   </Text>
                 </View>

mobile/src/screens/ScenesScreen.tsx

@@ -62,12 +62,18 @@ export function ScenesScreen() {
       }),
     initialPageParam: 1,
     getNextPageParam: (lastPage) => {
-      const loaded = lastPage.page * lastPage.per_page;
+      // Paginuj po has_more (źródło prawdy z fetcha per_page+1). `total` jest dla
-      return loaded < lastPage.total ? lastPage.page + 1 : undefined;
+      // list filtrowanych bounded ("1000+"), więc NIE nadaje się do liczenia stron.
+      // Fallback na loaded<total gdy stary backend nie zwraca has_more.
+      const more =
+        lastPage.has_more ?? lastPage.page * lastPage.per_page < lastPage.total;
+      return more ? lastPage.page + 1 : undefined;
     },
   });
   const items = data?.pages.flatMap((p) => p.items) ?? [];
   const total = data?.pages[0]?.total ?? 0;
+  // total bywa bounded ("1000+") dla list filtrowanych (q/tag) — patrz backend _COUNT_CAP.
+  const totalLabel = `${total}${data?.pages[0]?.total_capped ? '+' : ''}`;
 
   const activeCount =
     filter.tagSlugs.length +
@@ -133,7 +139,7 @@ export function ScenesScreen() {
           isFetchingNextPage ? (
             <ActivityIndicator color={theme.muted} style={{ marginVertical: 18 }} />
           ) : !hasNextPage && items.length > 0 ? (
-            <Text style={styles.muted}>{`${items.length} / ${total}`}</Text>
+            <Text style={styles.muted}>{`${items.length} / ${totalLabel}`}</Text>
           ) : null
         }
         ListEmptyComponent={!isLoading ? <Text style={styles.muted}>no scenes</Text> : null}

mobile/src/screens/SiteScenesScreen.tsx

@@ -67,12 +67,16 @@ export function SiteScenesScreen() {
       }),
     initialPageParam: 1,
     getNextPageParam: (lastPage) => {
-      const loaded = lastPage.page * lastPage.per_page;
+      // Paginuj po has_more (z fetcha per_page+1). `total` bywa bounded ("1000+").
-      return loaded < lastPage.total ? lastPage.page + 1 : undefined;
+      const more =
+        lastPage.has_more ?? lastPage.page * lastPage.per_page < lastPage.total;
+      return more ? lastPage.page + 1 : undefined;
     },
   });
   const items = data?.pages.flatMap((p) => p.items) ?? [];
   const total = data?.pages[0]?.total ?? 0;
+  // total bywa bounded ("1000+") dla dużych site'ów — patrz backend _COUNT_CAP.
+  const totalLabel = `${total}${data?.pages[0]?.total_capped ? '+' : ''}`;
 
   return (
     <View style={styles.container}>
@@ -120,7 +124,7 @@ export function SiteScenesScreen() {
         ListHeaderComponent={
           data ? (
             <Text style={styles.subtitle}>
-              {total} {total === 1 ? 'scene' : 'scenes'} · sorted by release date
+              {totalLabel} {total === 1 ? 'scene' : 'scenes'} · sorted by release date
             </Text>
           ) : null
         }
@@ -128,7 +132,7 @@ export function SiteScenesScreen() {
           isFetchingNextPage ? (
             <ActivityIndicator color={theme.muted} style={{ marginVertical: 18 }} />
           ) : !hasNextPage && items.length > 0 ? (
-            <Text style={styles.muted}>{`${items.length} / ${total}`}</Text>
+            <Text style={styles.muted}>{`${items.length} / ${totalLabel}`}</Text>
           ) : null
         }
         ListEmptyComponent={!isLoading ? <Text style={styles.muted}>no scenes</Text> : null}

mobile/src/screens/StudioScenesScreen.tsx

@@ -147,7 +147,7 @@ export function StudioScenesScreen() {
         ListHeaderComponent={
           <View style={styles.header}>
             <Text style={styles.subtitle}>
-              {data ? `${data.total} ${data.total === 1 ? 'scene' : 'scenes'}` : ' '}
+              {data ? `${data.total}${data.total_capped ? '+' : ''} ${data.total === 1 ? 'scene' : 'scenes'}` : ' '}
             </Text>
           </View>
         }

mobile/src/screens/TagScenesScreen.tsx

@@ -55,7 +55,7 @@ export function TagScenesScreen() {
         ListHeaderComponent={
           data ? (
             <Text style={styles.subtitle}>
-              {data.total} {data.total === 1 ? 'scene' : 'scenes'} · with playback
+              {data.total}{data.total_capped ? '+' : ''} {data.total === 1 ? 'scene' : 'scenes'} · with playback
             </Text>
           ) : null
         }

mobile/src/types.ts

@@ -166,6 +166,12 @@ export interface SceneListOut {
   total: number;
   page: number;
   per_page: number;
+  // has_more: czy jest kolejna strona (z fetcha per_page+1). Paginuj po TYM, nie po
+  // `total` — bo dla list filtrowanych `total` jest bounded ("1000+"). Optional dla
+  // wstecznej zgodności ze starym backendem (undefined → fallback na total w UI).
+  has_more?: boolean;
+  // total_capped: true gdy `total` to cap (jest >total wyników) → pokaż "{total}+".
+  total_capped?: boolean;
 }
 
 export interface MovieChapterOut {